Gas turbine systems are widely utilized in fields such as power generation. A conventional gas turbine system includes a compressor, a combustor, and a turbine. During operation of the gas turbine system, various components in the system are subjected to high temperature flows, which can cause the components to fail. Since higher temperature flows generally result in increased performance, efficiency, and power output of the gas turbine system, the components that are subjected to high temperature flow must be cooled to allow the gas turbine system to operate at increased temperatures.
Various strategies are known in the art for cooling various gas turbine system components. For example, a cooling medium may be routed from the compressor and provided to various components. In the turbine section of the system, the cooling medium may be utilized to cool various turbine components, including components in the hot gas path of the turbine.
Airfoils are one example of a hot gas path component that must be cooled. For example, both turbine buckets and turbine nozzles incorporate airfoils, and the airfoils are constantly subject to high temperature flows during operation of the gas turbine system. If the airfoils are not cooled, either the temperature of the hot gas flow must be limited, reducing the performance of the gas turbine system, or the airfoils may be at risk of becoming damaged and failing.
Various strategies are known in the art for cooling airfoils. For example, one prior art strategy flows a cooling medium through radial cooling passages that extend through the length of the airfoil. The cooling medium is then exhausted through the tip of the airfoils. However, many airfoils, such as latter-stage buckets, are too long and are curved along the length of the airfoil, preventing the radial cooling passages from extending through the length of the airfoil.
Thus, a cooling device for an airfoil that allows radial cooling passages to be utilized without requiring the cooling passages to extend through the entire length of the airfoil would be welcome in the art. Further, a cooling device that allows radial cooling of the airfoil and that allows the cooling medium to be exhausted from the airfoil along the length of the airfoil would be advantageous.